Fix crash on parseing invalid GLM syntax

diff --git a/src/math/interaction.c b/src/math/interaction.c
index d81eba5095b613231c5deef69d9e68f90c97ff27..746cc17fa1bcd72acaf0359a7824f1c214705c49 100644 (file)
--- a/src/math/interaction.c
+++ b/src/math/interaction.c
@@ -60,6 +60,9 @@ interaction_create (const struct variable *v)
 void
 interaction_destroy (struct interaction *i)
 {
+  if (NULL == i)
+    return;
+
   free (i->vars);
   free (i);
 }